(and one of Michael Bolton’s)
One of my testers took James Bach’s 3-day online Rapid Testing Intensive class.  I poked my head in from time to time, couldn’t help it.  What struck me is how metaphor after metaphor dripped from Bach’s mouth like poetry.  I’ve heard him speak more times than I can count but I’ve never heard such a spontaneous panoply of beautiful metaphors.  Michael Bolton, acting as assistant, chimed in periodically with his own metaphors.  Here are some from the portions I observed:

• A tester is like a smoke alarm, their job is to tell people when and where a fire is.  However, they are not responsible for telling people how to evacuate the building or put out the fire.
• (Michael Bolton) Testers are like scientists.  But scientists have it easy;  They only get one build.  Testers get new builds daily so all bets are off on yesterday’s test results.
• Buying test tools is like buying a sweater for someone.  The problem is, they feel obligated to wear the sweater, even if it’s not a good fit.
• Testers need to make a choice; either learn to write code or learn to be charming.  If you’re charming, perhaps you can get a programmer to write code for you.   It’s like having a friend who owns a boat.
• Deep vs. Shallow testing.  Some testers only do Shallow testing.  That is like driving a car with a rattle in the door…”I hear a rattle in the door but it seems to stay shut when I drive so…who cares?”.
• Asking a tester how long it will take to test is like being diagnosed with cancer and asking the doctor how long you have to live.
• Asking a tester how long the testing phase will last is like asking a flight attendant how long the flight attendant service will last.
• Complaining to the programmers about how bad their code looks is like being a patron at a restaurant and walking back into the kitchen to complain about the food to the chefs.  How do you think they’re going to take it?
• Too many testers and test managers want to rush to formality (e.g., test scripts, test plans).  It’s like wanting to teleport yourself home from the gym.  Take the stairs!